Final answer:
The difference between aria-labelledby and aria-describedby is that aria-labelledby is used to label an element, whereas aria-describedby provides additional descriptive information or context for the element.
Step-by-step explanation:
The difference between aria-labelledby and aria-describedby lies in their use for accessibility in web development. aria-labelledby is used to associate an element with another element that labels it. This is commonly used for form input elements or widgets that benefit from a visual label for users who can see and a text description for assistive technologies like screen readers. In contrast, aria-describedby provides additional descriptive text for an element, which might be used to offer more context or instructions, and is not necessarily a label. For example, aria-describedby could be used to describe the function of a button or details about complex content, such as a chart or graph.